Leg prosthesis



P 1949- u. K. HENSCHKE ET AL 2,480,856

LEG PROSTHESES 3 Sheets-Sheet 1 Filed July 9, 1948 Sept. 6, 1949. u. K. HENSCHKE ET AL LEG PROS THESES Filed July 9, 1948 3 Sheets-Sheet 2 IIIIIIIIIIIIIIII \l &- 9

adv AN'TQR YEV P 1949- u. K. HENSCHKE ET AL 2,480,856

LEG PROSTHESES 3 Sheets-Sheet 5 Filed July 9, 1948 INVENTORS.

ME/fl/ A4 #iA /A A f BY #4/1 5 6 M4 Patented Sept. 6, 1949 7 LEG PROSTHESIS ch K. Henschke and emanate? Dayton, e K

Application July 9,1948, Serial No; 37,745,;

(Granted under'the act of March 3, 1sss,- as

amended April 30,

The invention described herein may be manufactured and used by or for the Government for governmental'purposes without payment to us of'any royalty thereon.

This invention relates to artificial legs and more particularly-to artificial legs attachable to a thigh stumps'of amputees wherein the amputee can control the function "of 'theleg by shifting the center of gravity of his body and/ or by slight muscular efiorts of the stump.

One of the most obvious disadvantages of known artificial legs compared with the natural leg is the impossibility to stand on the artificial leg with bended kneean'dlto make slow knee bends. An a puteexnererere has no security against jackknifing and hfcan not 'naturally ascend or descend stairs or walk on inclines. Numerous mechanical asfwelli 'as hydraulic or pneumatic types of knee brakes have been suggested to fulfill the functions of muscular action in order to provide above the knee amputees with a better prosthesis but their reviewreveal's that the essential diificultydo'es not lie in the particular construction of the brake, but in finding a control for the brake thatwill work correctly for all phases of walking, stepping ueand down, etc. Automatic control by stepping'on the heel or on the toe, or both together, or bytthe bodys' weight have often been tried but none of these 'automatio systems can be used for all types of walking with;

out a switch installation for sometypes of walk,- ing, for instance, descending stairs. Such unnatural installations soon-become "an annoyance for the amputee. More successfully proved is the use of the so-called voluntary controls by special muscles. One possibility is thecontrol by means of one hand which can begraded very accurately and learned most speedily but since the amputee must rely on the free use of his hands more than.

an average person, this type of" control can not be recommended for practical use. Another possibility is the use of the abdominal muscles for control which has been quite successful although the necessity of an abdominal. belt may be ob jectionable for a number of amputees.

The present invention provides a control which achieves about the same functional results as the hand or the abdominal control without requiring any special attachment'outside the prosthesis. In carrying out this invention, the changing position of the center of gravityof the amputees body relative to a transverse axis located near the hip joint and more particularly in the area between the natural hip joint and the tuber of the ischium bon ortne pelvic girdle and/or the exertion of little efiorts in the stump, are utilized t ,control t e knee look. If the center of gravity, of the body anterior to this axis and/or the'stuiiip sed backward, the bending of the knee orjlockedi but, if the center otfgra c 161' to this axis and/or the stump p v fwardgthe knee brake or look is; unlocked 'fllie'location of that transverse axisnearthe 'hipfjointjhas the efiect that the shiftingof .the centerlof gravity of the .location of the avityj, Thus the trolling nieans friction by which be maintained u'nles a in order toehafige itf by the amputee by a .jerk of backward. ,I, I

To. make it easie'ri for theamputee to distinguishvbetween jthe braking and the. fully. locking ontrol z'vosition will 1m in force is exerted 'c ,canbe exerted 'stunip forward or position offth controlling means, the invention further provides ro r. anTelastically overridable step in thefjcour'seof.thcontifolmovement. The

position offthisj'stop.isadjlistableland'is.set so that the. knee -brak'e,lfwhen the control just touchesthe stop, yiel'ds' under 'the weight of the amputee with a rafteconvenient to .him in walk- 40 ing downstairs. and 'doiivnhillg'f By overriding this stop the amputee can lock thelbrake. fully which is useful, for instance, iniw'alking upstairs.

describedin the above paragraphs .butare com-,

5 ,mon in accordancewith this inventionv in that the socket which encloses thestump is not rigidly connected with thepppenpartof the knee joint but is made turnablerelativetothat partabout a transverse axis lwhich 'lies:near theehip joint a m e rt e 't t 3 the are bet e e as ajcontrolling riding on the V 'Tviil'ienfhe puts a ificiaLlegj because jg of. the" invention In order to eliminate-the disadvantageof walla. ing shocks of. the conventionalartificial leg, a suitable elastic element in connection with the i natural hip joint and the tuber of the ischium bone. Since such an axis can not be provided technically in a normal way, because it would for the most part be situated inside the amputees body, the movement of the socket aboutthe axis is achieved acc oitd guiding two'orn iore points of the lower part of it ,the presentinvention by the socket, along orbits, the center of which lies in that axis, or along tangents of such orbits, or along curves which run approximately on those.

tangents or approximately on the orbits themselves. this invention either by rollers and tracks, or by ball bearing sections, or by swinging levers, or by elastic steel bands, all this to diminish friction. By making the position of the guiding parts adjustable, it is ossible to choose the spacial location of the transverse axis mentioned aboy'e -at the convenience of the amputee.

A leg made inaQQQrdaiice withthis invention provides excellent, 'simul sequence of leg move the artificialleg is walking cycle,'jtlie kneewill be locked bythe operation of thekneeflbrakethrough the knee control. this phase is. produ ed A tendenc of the'lkne'e to buckle in he relatively stiff heel The guiding can be doneaccording totion of the natural, ts; Whenjtlie heel of .011" the floor during the '4 and/or little muscular efiorts of the stump are utilized to control the knee brake.

It is still another object of this invention to provide an artificial leg for above the knee amputees in which this motion of the center of gravity cfthe wearer. and/or little muscular efiorts-of his stump are 'utilized 'to rotate the socketed thigh part of the leg with respect to a transverse axis located near the hip joint and more particularly in the area between the natural hip joint and the tuber of the ischium bone to control the knee brake by guidingtwo or more points on the lower part of the socketed thigh part along orbits, the

center of which-lies in that transverse axis or bumper and'the slightly cushioned knee bending V is permittted "byv reasonv off thefelastic elements connecting theknee lock togabsorbl steppingv shocks. A completejjackknfifing' i'sprevented by the kneelocksl hthati le kneebends only as far as it is madepo's'sible, by the'ela'stic elements By the help ofth n'er'gy storedfin the elastic elements, thegleg straight" rolls over thelballgof t \foot All of these motions are coordin'a such a manner that thecenter of grja y erna ns nearl'y level as st ta imi i possible and is; sq m' h the same as in, the,

natural leg actiorljthatiits lartificial nature is barely recognizable, if 'atall; In walking downsta s or wnbi li r ii r sittinsdi wn, th v amputee if s hisfcenter cfe alvity' forward ari /or presses his stumpbackward until the controlling means touch the above 'rn'en'tionedf elastically overridable stop, The leg "thenyieldsfunder the weight of the bodyat ajat'e aai sti diat the c n v n e Mme/am tee. g

In walking upstairs oruph'ill, the arn'piitee. puts the prosthesis forward, and upward in a convenientlyi bended pfo' ltion then operates the control along tangents of such orbits, or along curves which run approximately on those tangents, or approximately on the orbits themselves.

It is a further object of this invention to provide a thigh prosthesis in which the thigh part of the leg is attached lQthe knee by slightly shiftable elements, thisshifting motion being transmitted by related elements toa knee brake controlling means andwhereinthe course of these transmission elements a small amount of friction is provided, by whicha, certain position of the controlling meansisgmaintaine'dunless a minimumiorc'e is exertedfby' the wearer in order to change it. 1

It is still anotherlobjpcjt'ofi thisinventionto provide a thigh prosthesis containing aknee brake and a voluntarily actuatedcontrolling means for the knee brake wherein the controlling movement causing engagementof'the brake is limited by an adjustable elastically overridablestop which is set so thatthejknee brake; if the control just touches the stop, yields under the weight of the amputee at a rate convenientto him in walking downstairs and downhill andwherein'by overriding the stop the amputee can lock the brake fully,

Itis a furthe'r'object ofthis invention to provide a thigh prosthesis having a knee joint in which the prosthesis includes-s a'kneelock containing elastic. means that resiliently permits slight knee bending during the first phase of the step while the knee is locked t maintain the center of. gravity of the wearer Substantially on the same levelthroughout the step andwherein the relatively stiff heel bumper is provided, which y b d s neaeeableith st of the e bumper serving to produce aflbending moment in p the knee joint after heeigcontact.

with a forcestrong enoughto override thestop',

thus. fully lockingjjthe prosth sis andlpasse's'over the stiff bended artific amount of friction means, the leg mainta s its pos l enough p ti ki and en n thenextlstep of thestairs h sunett. cle ranc At the top.

of the stairs the amputee disengagesgthe brake and straightens the, leg by forward movement and a Short wardierkbfth stum In all these walkingtypes, up; and downstairs and up and downhill thgelfastic element, which makes the knee lock resilient, serves as a shock absorbin means.

It is a primary object otthis'finventlon to provide an artificial leg :for above'the knee arnpui'ees that is capable q sim lating nat ai t motion in use without the necessity 'ofoutside controls,

It is another object of this invention to'provi'de a thigh prosthesis in which the motion of the center of gravity of the; wearer. with, respect to a transverse, axis lccatednear thehi joint and more particularly in'the areabetween the natural hip joint and the tuber of" the ischium bone i al 15g 15y the, small 6d w thi t e n o in It is still a further object of this invention to provide a thigh prosthesis'in which a pantograph or. an equivalent kinetic arrangement producing relative knee andjfootmov'ement includes a knee lock connected in the. pantograph by elastic means, wherein the elastic njeans resiliently permits slight bending during the f rst phase of the step while the knee is locke maintain the center of gravity of the'wearer substantially on the same level throughout the. step;

It is still another object of this invention to, provide a thigh prosthesis having a knee brake controlling means to brake, lock and release the knee brake in accordance with the shift of the wearers body. and/or littl e muscular efforts, in his stump transmittedthrough the thighparflt of the prosthesis, one element ofithis locking. arrangement being elastic to permit'slight knee bends during the stepping phase of ,the wearer -and to absorb 5 ments, the relative motion between the knee and the thigh about a transverse axis located near the hip joint and more particularly in the area between the natural hip joint and thetuber of the ischiumbone being transmitted by related elements to a knee brake controlling means, the

knee brake constituting a part'of' a pantograp-hinterconnecting the thigh part with the foot part effecting relative knee and ankle movement and the controllin means being effective to lock and release the knee brake in accordancewith the shift of the amputees body and/or little muscular efforts in the stump transmitted through the thigh part, one element of the pantograph connecting the knee brake beingnelastic to permit slight knee bends'during the stepping phase of the amputee and to absorb the shocks transmitted through the leg during the walking cycle.

These and other objects and advantages may become more apparent as the description proceeds when taken in conjunction with the accompanyartificial leg showing a number ofthe elements' in detail;

cross sectional view of Fig. 4 is a sectional View of a modified kneeelement guiding means;

Fig. 5 is another view of the modification of Fig 4 with parts broken away to show details of construction; and V i Fig. 6 is a fragmentary sectional View of another modification of the knee element guiding means.

Referring more particularly to Fig. 1, there is shown a thigh part it) of an artificial leg having a socket i 5 receiving the thigh stump i2 of an am putee with the thigh bone is shown in broken The thigh part it is connected to a knee lines. element iii in a manner later to be described and a shank i 6 is pivotally connected to theknee element at i! forming the knee joint. At the lower end of the shank is afoot I8 pivotallyconnected to the shank to form the ankle joint is.

The knee joint I! and the knee element l5'is fixed by rigid members 2| (of which only the far one is shown in Fig. l) supporting the pin forming the knee joint. Also pivoted on this knee joint i I is a fluid cylinder, generally referred to by the reference character 22, that has a cross pin 23011- I its lower end with bearing members 24 on the outer ends thereof operable in tracks 25 positioned longitudinally of the shank and on the inner wall surface thereof. Pivotally mounted on this cross pin 23 on opposite sides of the fluid cylinder are two elastic'members 26, preferably metal, which at their outer ends are pivotally-supported on the rigid members 2| of the knee'element at points 21 situated near or on a line through the knee joint and the longitudinal axis of the thigh part.

Also pivotally connected to the cross pin- 23 is pending application Serial No; 37,744, filed July 9, 1948. The lower end of the piston and rod component 32 is pivotally connected to the foot 5 part I8 at 33' through the agency-of a pair of upstanding plate members integral with the" foot and providing one component of the ankle therein.

joint; The pis'ton' of thef'rod comppne'nt t inward and'normal-position in the cylindrical' l component 31' rests against a' resilient member as which absorbs shocks imposed on the ball of the foot ina manner morefully'described in the' above named copending applicationl The "leaf' spring ifi is 'fixed with respect to the lowerend of the fiuid-cyIinderZZ in any well known manner with its free endfproducing 'a laterally bia'sing moment counterclockwise an the cylindrical cornponefitti to'produc 'ea pinching effect and fric tionbetweeh the two components of the -telescop-* ing'z eleine'nt's 39- "for the same reasons set out in our aforementionedcqpending application.

A rela'tively stiff heel bumper-31- has one end seated in'a -cup'38 fixed tothe foot part I8 and the other endseated a cup member-'39 that Q has a cylindrical extension 4|] slidableina tubular extension! i integral-with the shank l6 The upper endsfo'fthe tubular extension 4 HS threaded in which a scr'ew lz adjustable to regulate the compressive forces on the bumper and consequently 'limit the'plantar-flexion of the foot. The advantages of the3bumper-31 will become clearer as the -deseription-proceeds.

R'efrringmore'particularly tojFigs; 2 and 3 with occ'asional reference to Fig. 1-, thereis shown fragmentary views with the parts in section of the'connecting 'structurebetween the thigh parti'andtheknee-element l; and'-the structure of thefiuid cylinder element -22 with the related'knee controli-"flh'e lower end of the thigh part Ill has i a saddle member 56 with four downwardly extending portionstheach-"of which has a. bore 52 therein to form aligned pairs {in thefforward' and rearwardpart of the knee element parallel to the axis: of the knee joint I'Ii Set within eachbore 52 is a guidingeleinent 53 which has-two notchesjfl cut in' the circumference "thereof to receive the ported in the downwardly extendingportions 5 I; By manipulation of the set screws 55, each of the guiding elements-53 can be rotated to change the angle of an outwardly facing ball track 56 The knee element l5 includes, as heretofore mentioned, apair of rigid members 2| through which a pin 6! extends forming the knee joint 1. The shank 16 is pivotally attached to the-- outer extremities of the pin 6| and so formed to be rotatable through approximately degrees with respect to the thigh part In. The upper ends of the rigid 'members 2] have bores 62 therein in pairs having centers equal in distance to the centers between the pairs of bores 52in" the'member of the thigh part.

an inwardly facing ball track 64 therein. Two l balls 65;p'referably steel, are placed in the ball tracks 56, 64 of each of the companion guidingelements 53, 63, the two balls 65 being short of filling the lengths of the ball track to permit a small amount of relative movement between the thigh part It] and knee element [5 in a direction of the tracks56, 64. The: balls 65, are, of course, retained in their tracks 56, 64 by the surface of the bores 52 and 62 of the members 50 and 2 L respectively. The fluid cylinder mechanism 22 is, as hereto fore described, pivotally connected to the knee joint l1. This connectionis established by-a piston member 10 of the fiuidcylinder mechanism having a tubular stern extensioni'll extendin ioute 1 5 7 Within each- J ofthese bores 62 is aguiding element 63 having 5 the actuator, endportion of a-valvestem 16 having. a, head portion. 11; cooperatively, related with a valve seat ,18;within the piston] 0:120 control passages 19 and 80}; Theval-vestem- 16-..passes:

knownmeans Ag piston' 9f]- is slidable; in. the

upper portion of; the: hydrauliccylinder; between! thering. Strand the; piston] 0 with-an opening oon-- centricallythereof, to slidably:- accommodate. the tubular stem 1 I. l The piston-90 has 1 seal-in'g ;rings 9| and 9 2. to eliminate fluidvleakagebetween'the' piston 90,, cylinder-wallandtubularsteme'll.re

spectively. The piston QIt-is'Jimited-in itsdownwardmovement by a-shoulder 93*7OI'1' theinner surf ace ofl the fluidcylinder. A'spring Qkisinterposed under compresionbetween the ringtSJ-and the piston -9,0 such thatfluid, as oil; may, be introduced. in the part of fluid cylinder formed byythe piston; 9ft and.,the,lower1end-,-ofthe cylinder, and shall be retained: under pressure to the amount exerted by the.; force of the springj94; In this manner-,the pistoniIfl-works ina fluid under pr es-.

sure andzthere; is little chance ofair pockets fouling the: operation thereof. 'll'urthermore, the spring and piston compensate for thestemv H volume. and temperature expansion. of the;- hydraulic fiuidas. well asproduce a slight leg extensionbias: by reason of the-springx ttending to extend thehydraulieelementl, 1

Within. the divided. portion; H ofthe tubular stem-'11 is a bent lever mil -pivoted at LBJ such; that; one arm; is contiguous to the-actuating end of the valve stem Hi. This arm has an elongatedv slot; If zethereinthat receives: a-pin-i I-M' carried by the actuating end of the valve stem 16. The other end 'ofthe bent lever has. attached thereto a Bowden; wire I134 that passesthroug-h, a. flexible casingJIlki-to connect inan eyelet IIJIisituated-inv the saddle member 59-. One end; otthe; flexible casing- I 95- is physically attached to a thetubularstein It and the-other endis attached tothe members 21in any well known manner; Any relative movement between the.- thigh part III? and the knee element I5 through the ball: and track; con-z nection. will operate to movethe; Bowden wire lfl i 'within the casing" II!5-'tov rotatethe bent lever I00= about its pivot; IM to actuate the. valve whereby the piston: III; may be fluidly locked or unlocked: in the fluid cylinder;

The upper endof th tubular'stem M.- just below the dividedportion l4" isicylindricallyenalarged; at III! to receive aycup-shaped piston; I IrI= slidablein thecylindricatportion I III; The, piston I I I is adjustable to height by an;adjustableaeccen:-- triepin: IgIZ... Above the piston; Ii I Ii is a sleeve I-;I=3. slidable on the valve stem 16 and biased upwardly from thepiston I. I; I: by a spring Ill:4-. a'gainsta nut II5:ad-justable oh; the stem 16;. .The lower end of the nut IJI 5.islcapableof passing through an open-i ing' in thetoplof the cylindic ically enlargerhportiona 7 divided at?! tfor, a short distance-toaccommodate laterally against the sleeve'lla; producinga cer- A tain amount of friction between the sleeve andthe surface of the valve stem; Hi.- The upward movement of this valve stem is limited by an eccentric I iii. If pull exerted on the Bowden wire I04, the lever I09 pushes the valve stem Hi down:- ward. Th first part of this movement occurs against the friction of the sleeve I I3 until nut I I5 engages the upper surface of that sleeve. opening'of the valve Tl, I8 is then just small enough to provide for a slow jacknifing of the prosthesis as it is suitable for walking downstairs or downhill. If the amputee wants to lock, the brake entirely, he shifts his center of gravity somewhat forwardly and/or presses his stump backward. The strong force on the Bowden wire I04 overcomes the bias of the spring H4 and the valve stem '55 continues to move downward until I I fl but the sleeve ill large; en h to engage the casing surroundingthis opening. A spring- IIFatdjustablybiased bye-cap screw H3: presses:

siderable muscular efforts WQllld be required; to

valve ll, 58 is closed completely; As soon as the force which the amputee applies will be lessened thevalve stem shifts'back until the upper surface of the sleeve II- again engages the casing H0;

- pelvis and thereby his center of gravity forward or backward. He also may decide by the degree of shifting whether the knee motion will be locked completely or will only be braked, the latter due to a partial closing of the valve TI, 'i8

Since the movement of the valve stem.- 76. is braked by the braking sleeve I l-Hii on its top end the valve stem tends to maintain its momentary position even if the leg is lifted from the ground floor and the amputee is no longer able to put weight on the prosthesis. He may, however, change the position of the valve stem without touching the ground floor by short jerkwise forward and backward motions of the stump.

To understand this invention-more thoroughly it is believed that the purpose of the structure as it directly relates to the amputees body should be brought out. Referring again more particularly to Fig. 1, the thigh bone I3 makes a hip joint with the an'iputees bodypelvic girdle at IZt. It has been found that the centerofi gravity of thebody of the amputee is in a region; of'the body somewhat above the hip joint as indicated by the reference character I21. The location of the ischiumbone is designated in dotted lines and indicated by the reference character I22. In-

accordance with the presentinvention, the center I of the gravity oft-he amputees body relative to. a transverse axis; which is herein designated. by the reference character I723- located in the area, between the hipjoint and the ischiumbone, will beutilized to control the 'knee brake. The adjustable screws 55 are manipulated tov rotate the guiding elements 53 until the. ball tracks. 56 are tangent toa, circle whose center lieson a transverse axis I23; The; guiding, element 53- will be rotated accordingly: In this condition, the amputee causes a shiftrinth knee element tov con trolthe knee brake by the'naturalshift of his body and; .only thenormal; muscular action-in the stump. If the transverse axis werefmoved outside the area between the. hip jointand' the tuber of the, ischium boneby changing the ball tracks 56, B4 counterclockwise or; clockwisev respectively, torques. would be imposed; on the; stump and con.-

' shift the knee and thigh elements to control the knee brake. It is an important feature of this invention to establish a transverse axis and to guide two or more points of th lower part of the I 110 along slots I5 I, in the foot portion of the L -shaped structure 5|. An adjustable screw I52 is rotatable and axially immovable in each of the portions 5I' and is threaded through the block I50 stump socket along orbits or tangents of such, 5 to impart movement to the block I50 along the orbits as :shown and described, or along" curves which run approximately on these tangents or approximately on the orbits themselves, the center of the'orbits orcurves lying, on the transverse axis, to avoid any .lundesir'able; torques being placed on the stump.

An amputee wearing such an artificial leg will be able to walk quite naturally. When the artificial leg is'placed forward for a step, the shank will be swung forward in lihe'with, the thigh and the Weight will be first placed on theheel. The stifi bumper 31 causes a bendingmomenton the shank to carry the knee element forward. The center of gravity of the wearers body is sufficiently anterior to the transverse axis I23 to create a turning moment on the stump tending to rotate the .stump counterclockwise about the transverse axis 123 that causes a shift in the saddle member 50 :to pull the Bowden wire I04 to setthe -valve-l1. well on the valve seat 18 to fluidly lock the piston; I in the cylinder preventing knee bending. However, due to some elasticity. of the st'rap's-26-,-a slightknee bend, common irr natural walking, is permitted since only a slight elongation of the straps 26 allows the knee to bend in accordance withthe elasticity of the straps in view of" the pivotedpoints I1, 23 and 21 being in substantially or approximately a straightline. As the body passes over this le and fullbodyweightis onit; the knee may be flexed more in a manner natural of walking which eliminates the necessity-of pole vaulting over' this leg. When the'body weight-is shifted to take a'step' with the 'goodleg, theartificial leg will be posterior to the wearer's body, the weight 4 'of the bodyj'willmove up on the ball of the foot lockthe cylinder to releasethe knee for freemove- 'ment.- The swing of the th-igh'forward causes sufiicientknee'bending to allow the foot to clear the noon-particularly by-means of pantograph elements 'I9, 23; 30, and 33,-for the succeeding step when the-knee will againbe locked as before for the step. If for-any reason the knee looking means-fails ,the screw 42 maybe run outwardly to release thecompressive forces on the heel bumper and 'decrease the bending moment on the'knee joint occurring on heel contact;

Due to the differentcharacteris'tics of walking of different" peoplejthe spacial location of the transverse axis I23 can be located for the particu- 'lar convenience of the amputee and for amputees 0f difier'cnt height.""

The guiding between the thigh part and the knee element I can be done, according to this invention, "in various'waysi One modification is shown 'in' Figs. 4'and"5 whereinlike'elements of like reference characters and correspondingelement's of'the reference 'characters'are primed.

:Saddle member" 50" attached to the socket I I has depending "L-shaped' portions' 5 I in' which are ""rectangularly shaped blocks rl50'that are slidable adjustable screw.. Plates 2| have overhanging portions I above the L-shaped portions 5I' and an eyelet. I55 threaded or otherwise fastened to the overhanging portions I55. A link I51 passes .through each eyelet I56 and through a corresponding eyelet. I58 on the block I50. In this manner, the four blocks I50 in the knee element can be adjusted to fix the transverse axis in the 'wearers' body for the purpose set forth in the description of Figs. 1, 2 and 3;

The guiding elements may take the form of swinging elastic steel bands, ball bearing sectors, swinging levers, or a number of ways of construction which would-be considered possible by a mechanic skilled in the art in view of applicants disclosure in Figs. '1, 2 and 3. However, applicants show some ofv the preferred forms, another form being shown in Fig. 6 wherein the member 50" attached to the socket II, has elastic bands I60, as strip steel, fastened to the member 50" by screws lfiLy The lower ends of these bands I50 are attachedby; rivets or the like to blocks I62, adjustably movable in slots I63 by adjustable screws I64 in-the members 2|". The Bowden wire I04, "I05;-can=be connectedto the relatively movablepa'rts 50" and 2I;in any well known manner to provide control of the knee brake.

- It is to be understo'odthat many modifications and changesmay be made in'the various elements' and features of'applicants invention to carry out theprinciples and'functions attained byapplicantsdisclosureand applicants desire to be limited onlyby the scope of the appended claims.":*"-' y We claim: l

1. A voluntarily. controlled thigh prosthesis comprising'a leg ha'vinga shank part including foot; and thigh parts consisting in an upper so'cketed element and 'arloweriknee element, said knee, element being connected by a knee joint with said shankpartand saidsocketed thigh element being slightly turnablerelative to said knee element abouta'transverse axis which lies near "thehip joint and more-particularlyinthe area between-the natural hip joint and the tuber of theischium bone of the'wearer; and acontrol- ,lableknee brake; said knee brake being associated by mechanical means with said knee element and said shank part, and means by which said relative turnable movements between said socket thigh elements and said knee element are operative to control said knee brake.

2. A voluntarilycontrolled thigh prosthesis as set. forth inclaim 1 wherein said knee element supports guidingelements connected to said socketed thigh element to guide said socketed thigh element with respect to said knee element about said transverse'axis.

'3. A voluntarily controlled thigh prosthesis as set forth in claim 2 wherein said guiding elements consist of more than one'complementary ball track in said kne'e element and acompanion complementary ball track in said socketed'thigh element, each composite ball track'containing 'at least one ball having limited'rolling movement "therein, said composite ball tracks being angularly adjustable to position said transverse axis.

' 4. A voluntarily controlled thigh prosthesis as set forth in'cl'aim 1 wherein said means; by which said relative tur n'able *rrfovements are operative to control said' kneebrake, contain friction'elejment s for fri'ctionally "maintaining control positions until a minimiim force is exerted to change them.

5. A voluntarily controlled thigh prosthesis as lock the brake i'ully.

6. 'A voluntarily controlled thigh prosthesis as set forth in claim "wherein said mechanical means associated with said knee'element and "said 'shank-partdn-cludes elastic'element for resiliently "absorbing shocks on said prosthesis in'any angle-of the "locked knee joint.

'7. A voluntarilycontrolled thigh prosthesis as *set forth in claim -1 wherein said .shank' part and foot part are connected by'an ankle joint, said ankle joint having a'rel'atively stiif disengageable heel bumper tor -producing"a fforward movement of said "k=neelenient whenever the heel contacts the floor efiie'ctin g sai'd relative turnable movement'betweensai'd sock'eted thigh elemerit and said-kneeelenient.

' 8. "A voluntarily controlled "thigh i prosthesis as set term in clairn '-l whereinfsaid controllable knee brake is a hydraulic cylinder having piston and cylinder operating ele'nients, said "hydraulic brake having a'valvemeans controlling'the flow of hydraulic'fiuid to opposite sides of-said' piston element, the "valve means having an actuator V operatively connected to said-so'cketed thigh'ele- 'ment andkne element to cohtrol saidhydraulic brake in accordance with relative sockete'd thigh element and knee element movements.

9. A voluntarily controlled thigh prosthesis as :s et'forth' in claim 1 wlrer em said shank' partand foot part are connected by an "ankle *joint, and

said mechanical -means 'associatin'g 'said knee brake with said element an'd-said shank part includes a "kinetic 1 arrangement 1 connecting said foot part with said kneeelement tor -producing interdependent kneeandankle movements.

10. A thigh prosthesis comprising a 's'ocketed thigh part, a knee -element, a i shank part and a foot part, said shank-part being journals-"d to said foot I part at an ankle joint and 'journaled to said knee elementat akfiee-"joint; guiding eler'nents "interconnecting -'s d 's'ocketed thigh part with said knee i element to provide limited turnable movement of saidtl i igh part about a transverse axis-situated in a wearer's body, 'said "guiding elemen-ts biiig slidabiy'adjustable to position transverse axis in thearea of the "wearers body 'nar thehip ioint and more particularlyf between the natural hip j oint and the tuber of the --ischiu'mbone' to enablethe wearer to efiect rotation of said thighpartinapredetermined -'directi'on*with respect to said knee element-b'y selective-shifting of the body center of gravity and little muscular efio'rts "of the stump; 1 a hydraulic knee "brake interconnecting said thigh andsl'iank parts, f said 'knee brake being "under the control *of "an actuatable element transmission elements to transmit said' rel- 'ativeturnable' movement-ofisaid thigh part with respect tosa'id knee element to"said"actuatab1e element of said' -kneebrake wherein'natural leg movements may be performed at the of the "overridable stop which is adjustable to transmit 12 warer'by a selective body center of gravity'shift andlittle muscular eficrtsof'his stump.

11. A thighprosthesis-asset forth in'claim 10 wherein said guiding'el'enients comprise four pairs of companion roller tracks on said knee element and lower thigh'p'art,'a'ndro1ler means in'each pair of roller tracks.

12. A thigh prost-hesis as set forth in claim 10 wherein said "guiding elements comprise four links suspending the lower end of said thigh part on said knee element.

13. A'thigh prosthesis' as set forth in claim 10 wherein said guiding elements are four swinging elastic-bands suspending the lower'en'ds of said 'thigh'part on said knee "element.

14. Athighprosthsis'as set forth inclaim 10 wherein said transmission elements transmitting said relative turna'ble movement to said actuata- -ble element'contain friction elements for friction all maintaining control positions unless a minimum t'orce'is exerted to change them.

1 5. 'A thigh prosthesis-as set forth-in claim 10 wherein said transmission elements transmitting said relative turnable movement to said actuatable element'contain anelastically overridable stop which isad'justable and determines by its adjusted riosition 'a yielding rate of said knee brake which is convenient'for the amputee in walkingdow-nstairs and'downhill and the overriding of which -enables the amputee to lock the brake fully.

'16. A thigh'prosthesis asset'iorth'in claim 10 whereinthe interconnection'of said knee brake fand'said thigh and shank parts incorporate elastic elements" providing slight knee bends during knee brake engagement to absorb walking shock-s, and wherein said "ankle joint contains a relatively st'iff' disengage'able heel bumper to initiate said 'sl-i g'ht'k nee' bends whenever the heel contacts the floor.

17. A thigh prosthesis asset forth in claim 10 wherein said interconnection of 'said knee brake I and saidthigh and shank parts include a kinetic I arrangement connecting said fo'otpart with said "knee element forproduci-ng' interdependent knee "and ankle movements.

18. A thigh prosthesis comprisinga socketed thigh part, a knee elemen'tfla shank part and a 'foot part; saidsliank part being'iournale'd to said foot part'at an ankle joint-arid journale'd to said kir'i'ee elementat 'a'kn'ee' joint; guiding elements interconnecting said s'ocketed thigh part with said "knee element to provide limited turnable' movesrient 'ofsaid thigh partabout 'a transverse axis situated ina wearers body, said guiding elements 'being slidably' adjustable to position said transverse axis in the "area of the wearers body near the hip joint and more particularly between the natural'liip joint andthetuber of the ischium bone to enable the wearer to eifect'rotation of said thiglr part in a predetermined direction with re'spect'to said kn'ee' element by selective shifting "of the body center of gravity and little muscular efforts of the stump; a hydraulic knee brake interconnecting said thighand shank parts, said knee brake being under the control of an actu- -*ata'ble elementcontaining-friction elements for .f'rictiona'lly' maintaining control positions unless a minimum force isexerted to change them; transmission elements containing an elastically "said relative turnablemovement of said thigh part with-respect to'saidtknee element to said 7 actuatable element 'of' said knee brake wherein natural leg movements maybetperformed at the will of the wearer by a selective body center of gravity shift and little muscular efforts of his stump and the adjustable overridable stop determines by its adjudged position a yielding rate of said knee brake which is convenient for the amputee in walking downstairs and downhill and the overriding of which enables the amputee to lock the brake fully.

19. A thigh prosthesis as set forth in claim 18 wherein the interconnection of said knee brake and said thigh and shank parts incorporate elastic elements providing slight knee bends during knee brake engagement to absorb walking shocks, and said ankle joint contains a relatively stifi disengageable heel bumper to initiate the slight knee bends whenever the heel contacts the floor.

20. A thigh prosthesis as set forth in claim 18 wherein said interconnection of said knee brake and said thigh and shank parts include a kinetic arrangement connecting said foot part with said knee element for producing interpendent knee and ankle movements.

21. A thigh prosthesis as set forth in claim 20 wherein said interconnection of said knee brake REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 523,329 France Apr. 19, 1921 530,887 France Oct. 12, 1921 OTHER REFERENCES Report on European Observations by Commission on Amputations and Protheses. Received in Division 55 of the Patent Ofiice February 12, 1947-pages 130 and 131. 

